Fabric coating, drying, and solvent-recovery apparatus.



c. F. HOPEWELL. FABRIC COATING, DRYING, AND 'SOL VENT RECOVERY APPARATUS.

' APPLICATION FILED OCT. 2?, I9II.

4 SHEETS-SHEET I Patented Jan. 16,1917.

c. F. HUPEWELL.

FABRIC COATING, DRYING, AND SOLV ENT REfiOYERY APPARATUS.

' APPLICATIO N FILED OCT. 2 7, 1911.

' 4 SHEETSSHEET 2.

Patnted Jan. 16,1917.

c. F. HOPEWELL FABRIC COATING, DRYING, AND SOLVENT RECOVERY APPARATUS.

APPLICATION' FILED OCT. 2h 191 1.

Patented Jan. 16, 1917.

4 SHEETSSHEET 3.

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APPLICATION FILED OCT-27.1911.

Patente diJan. 16f 1917.

4 SHEETS-SHE T 4.

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cHAnLEs F. HOPEWELL, or NEWTON, "MASSACHUSETTS.

FABRIC COATING, DRYING, JANQD SOLVENT-RECOVERY APPARATUS. 4

Specification of Letters latent. Patented Jan. 16, 1917.

Application filed October 27, 1911. Serial No. 657,176.

To all whom it may concern:

Be it known that I, CHARLES F. HornWnLL, a citizen of the United States, residing at Newton, county of Middlesex, State of Massachusetts, have invented an Improvement in Fabric Coating, Drying, and Solvent-Recovery Apparatus, of which the following description, in connectionwith the accompanying drawing is a specification, like characters on the drawing representing like parts.

This invention has for its object to provide an apparatus for dryingcoated fabric in which the coating compositioncontains solvents which are usuallylost iii-drying, but which are of value when recovered, and to reclaim these solvents so that they may be 'used again or for any other desired purpose.

The invention provides an apparatus in which air is practically eliminated as a dry-' mg or absorbing agent, and in which the only material function of the air entering the apparatus is to equalizeexternal and internal pressures upon and Within the vapor izer. This rendersthe apparatus of high efficiency because no useless heat is required to heat the air and'because. the consequent loss by refrigeration is proportionately lessened.

In the apparatus of this invention heating is performed bydirect contact or by immediate proximity instead of by air convection and preferably rotary mangles are employed encontrolling the feed of the fabric so as to maintain it in smooth and taut condition longitudinally and laterally, or throughout its .surface as it'passestherethrough. For

this purpose suitable let-oft and take-updevices are provided, thegoods are fed at. constant speed, and the'man'gles are crowned on their peripheral surfaces.

In this apparatus danger from explosion "due .t'o'static differences of electric potential are practically eliminated because the apparatus is made of metal and grounded by its connection through the heating circulatory systems. Inaddition provision may be made for the discharge of a jet of steam into the apparatus, and safety devices are provided allowing gases from any possible explosion to pass into a flue: without injury to the apparatus. The apparatus provides for the drying of the entire length of the fabric by the use of v awrapper or apron, which being attached to the end of the fabric allows the entire-length 4 f to pass through the machine, and which remains in the machine to enable subsequent lengths to be drawn in.

The'apparatus is further so arranged that the fabric enters and leaves at'the same end.

The apparatus is entirelyautomatic in its action, so thatfa mimmum amountof' attendance 1s required.

The apparatu's alsoprovides for the coat mg of the fabric ust prior to its entrance to the vaporizing chamber, vvhichalso preferably serves as means for sealing the entrance to the vaporizing chamber" a'gainstthe paschamber. V1eWed as an I entirety the apparatus I handles the entire operation automatically in a minimum amount of space, with a maXimum amount ,of efliciency, and with a minimum amount of labor. I

These and other features, of the invention will more fully appear from the accompanying description and drawings, which illus trate the preferred but notthe only form of apparatus embodying the invention, and'will be more particularly pointed out in the appended claims.

The drawings illustrate the pieferredform of apparatus embodyingthe invention, but f it is obvious that the invention is notto be restricted to the particular construction and arrangement illustrated.

Various changes may be inade in accord-- ance with the principles of. the invention set loi forth in the specification and Within the limits defined by the claims.

In the-drawings; Figure 1 is a side elevation of the apparatus embodying the invention. Fig." 2 is a detail in plan of a portion;

of the take-up roll and its driving mecha-- nism. --Fig. 3 is a central vertical cross section of the cgnst'ruction shown in Fig. 1,

omitting the condenser, let ofi and take-up. Fig. 4 is a transverse verticalcross'section of the vaporizing box taken through the axis of the rear mangle. Fig. 5 is a top plan view partially in cross section of the forward end of the apparatus with the hood covering the spreading devices removed. Fig. 6 is an enlarged detail view invertical cross section of the forward upper portion of the construction shown in Fig. 3. Fig. 7 is an enlarged detail in front elevation showing the construction for sealing the lower opening for the fabric of the vaporizing box- The vaporizing box through which the fabric is passed and in which the fabric is heated to dry the coating, is constructed to inclose a space for the collection of the evaporated vapors which shall be of a mini- 'mum size in order to secure efficiency and economy. In the construction illustrated the vaporiziiig box is shown as a generally rectangular elongated box, while the heating appliance comprises a pair of heated rotary mangles comprising rotalry heated drums and cooperating heated backing plates. These mangles located in the box reduce the size of the cl amber and the chamber is still further rec uced iii its size by other devices which will appear. The vaporizing box is preferably madel of boiler iron or other suitable metallic construction,.

so that it is of suflicient strength to protect the operator from any minor explosion which might possibly occur, and it is also provided with an autoimitically acting vent pipe to. relieve the pressure due to an explosion. "I ii the preferred form of the device hot water is circulated through the rotary mangles and backing plates, and this stream of water circulating through the metallic,

construction of the vaporizing box serves as a ground connection to dissipate any differences of potential which may take place in quence well nigh impossible.

While the apparatus is preferably heated byhot water, steam may be employed, and the construction illustrated is practically equally available for use with either heating agent. Other heating agents may be employed so long as the elements of the appa ratus are heated to the required degree, which is usually not over 180 degrees in the drying of fabric coated with a composition containing one or more volatile solvents.

While. the heating elements are shown as two heated rotary mangles andsuitably dis- 4 posed backing plates, the number and character of these elements may be varied, provided thatthe essential feature of drying the fabric from the back out through the coating by direct or radiated heat as distinguished from air convection, is retained.

In the particular construction illustrated the vaporizing box comprises vertical ribbed side plates 1, resting upon the floor or other suitable support, and secured togetherat their forward ends by a rectangular front plate 2; At their tops the side plates are secured together by a top plate 3 shown. formed in sections, the foremost section 3 formed in two difiereiit planes to increase the height of the vaporizing chamber at the forward end. This foremost section is also secured to the front plate 2. The side plates 1 are further secured together at the back and the bottom of the chamber by sectional hollow mangle back plates i to 16 inclusive. The sectional plate 4 is bolted directly to the rear transverse section of the top plate. The sectional plates 11 and 12 are bolted to the transverse plate 17, and the sectional plate 16 is bolted to the transverse bracket plate 18 which is bolted to the front plate and to the side plates, while the flanges of the several sectional plates 4% to 16 inclusive are bolted together as shown, and at their ends to the side plates 1. The vaporizing chamber is, therefore, that inciosure which exists between the side plates 1, the upper portion of the front plate 2, the top plate 3, the transverse plates17 and 1S, and the several sectional plates 4 to 16 inclusive, but the area. of this chamber is very materially reduced by the rotary mangle's, by an additional heating section, a drum and moistcn ing tank therefor, and other appliances CO1- tained therein, all to be described, as well as by the hollow transverse filler 19 inserted between theside plates 1 for the purpose of reducing the area of the chamber.

The only openings into the chamber are those which will be described for specific purposes, and the openings for the admission and exit of the fabric are sealed by appliances to be described, so that there is little opportunity for the-escape of vapor from or admission of air to the chamber; ()nly so much air allowed to enter the chamber as sufficient to maintain the pres sure in the chamber at substantially that of the atmosphere.

The fabric in its passage through the vaporizing chamber is maintained in a. taut condition so that it may be perfectly smooth and unwrinklcd while the coating is being dried. This result is secured by let-off and take-up devices for the fabric as it enters and leaves the vaporizing chamber, and these devices will be described In addition, the peripheries of gles are crowned in the center in the man as shown in the drawings, which aidsin keeping the fabric smooth and maintaining -1t in a.

straight direction during its passage.

In the form of apparatus shown the fabric is coated.immediately prior to 1ts admission to the vaporizing chamber,'and a spreading mechanism is employed to seal the admission opening against any material passage of air or vapor, the body of dope being applied to the fabric acting as anto seal the admission opening of the chambeer in which the coating is dried and the vapor of the solvents collected is supported by'a separate frame bolted to the forward upper end of'the -vaporizing chamher, but slightly separated therefrom 'by the rectangular frame 20lfformed of suitable heat insulating material. Alined slots 21 and 22 in this frame 20 and the front plate 2 of theyaporizing chamber permit the passage of the fabric into the yaporizingphamber. The frame 20 presents in its upper portion aehamber 23, the front wall of which is completed by the spreading knife 24 which is supported on a cross bar 25 journaled at its ends in bearings 26 inbrackets 27 bolted to the frame 20. Hand levers 28 extend forwardly from the cross fastened to the back of the frame 20. From this point it extends beneath the spreading knife 24, thus forming the bottom of the chamber 23, and around a roller 32 to a bar 33. The roller 32 is journaled in the horizontal arms 34 of a bell crank lever fulcrumed at 35 in bearing blocks 36 bolted to the frame 20. Depending arms 37 of this bell crank lever carry'in their lower ends adjustable screws 38 abutting against the frame 20, and by means-of these; screws the bell crank lever may be swung about its fulcrum 35 to raise and lower the roll 32, and consequently adjust the horizontal position of the sheet metal plate 3 1 with respect to-the edge of the spreading knife.

The cross bar 33 is connected by helical springs 39 to levers 40 fulcrumed :at 41 on brackets 42 bolted to the frame 20, and these levers 40 carry in their lower ends adjusting screws 43 also abutting i .against the edgesof the plate 31.

against the frame 20, whereby the longitudinal tension on the sheet metal plate may be varied to secure the proper cooperation of the plate with the spreading knife.

Directly in front of the spreading knife and belowvthe dope the sheet metal'plate 31 is perforated as indicated at 300. A closed metal casing 301 is secured to the bottom of the plate 31 beneath these perforations and connected by atube 'and a suitable suction device whereby a partial vacuumis produced beneath the perforations. Hence if any pit marks or pin holes appearin the fabric after coating, the next time the fabric passes through the appara' .tus the dope will be drawn'by suction into these pit marks or pin holes and fill them. A generally rectangular hood 810 of sheet metal or other suitable material fits over and completely incloses the entire upper portion of the frame'20 and its connectedparts. The front lower edge of the hood rests upon the top of the fabric as it' is fed over the plate 31, and the sides of, the hood fit This hood acts as an additional check to the escape of-vapors from and the admission of air to the vaporizing chamber and-an ex tension of the vaporizing chamber formed in the frame 20.

.A suitable let-off device for the fabric is shown in 'Fig. 1 mounted in front of the spreading apparatus. This letofi' device is shown as comprising'a roll 4.00, upon which the fabric is wound, and africtlon brake 401 provided with adjustable weights 402, so that the friction on the roll may be varied to place more or less tension on the fabric. The fabric 49 passes from the letoff device over the sheetimetal plate 31 beneath the spreading knife and through the slots 21, 22 into the vaporizing chamber. The dope is fed through a. pipe 103 in front of the spreading knife and the amount spread upon the fabric as it passes is accurately controlled by adjusting the sheetmetal plate 31 withrespect to the spreading knife by means of the set screws 38 and 43. The dope extending across the fabric where it contacts with the spreadingknife seals the chamber 23 along this line. while the felt plates 47 restingagainst the flexible plate 31 at each side of the fabric seal thechamber 23 along the side lines so that-any material escape. of vapor from the chamber 23 is prevented, while the hood 310 extending over all acts to still further minimize the escapeof any' vapor-into the surrounding atmosphere; in effect forms part ofthe vaporizing chant ber, being connected thereto by'the slots 21' and 22, and the'vaporizing chamber as a whole is thus securely sealed against any material escape of vapors at thebpenihg for the admission of the coated fabric.

'l-he'chamber 23 The fabric upon receivingthe coating passes immediately into the vaporizing chamber and no opportunity is afforded for the rem( al of superfluous dope from the back of the spreading knife,'or for inspecting or cleaning or removing imperfections from the freshly coated fabric. To obviate this mechanical devices are provided automatically operated for that purpose. Convenient mechanisms for effecting this purpose are disclosed in my co-pending application No. (321,967, tiled April 19, 1911.

A shaft 77 extends transversely through the vaporizing box near the front wall and is driven at high speed by any suitable connection with one of the driven parts of the apparatus. This shaft carries extending tangentially therefroin a series of knives 78 which extend across the fabric and are so arranged as to swing against the upper surface of the fabric and remove therefrom any foreign matter or imperfections.

The fabric is supported accurately in the path of the knives '78 by means of a table 79 extending beneath the fabric and carried by a bracket frame 80 pivoted at 81 to stands 82 bolted to the front plate 2. The rear of the bracket frame 80 abuts against an adjustable set screw 83 extending out through the front plate 2, and by means of this set screw the table 7 9 can be raised and lowered to bring the fabric. into proper relation with the revolving blades 78. 1

A receptacle shown as a rectangularbox 84: is mounted in bracket arms 841. depend ing from the top plate section 3 in the rear of the revolving knives. An inclined apron 85 leads from av point adjacent the fabric out into the mouth of the receptacle which faces the knives, so that any matter removed by the knives from the fabric is thrown upward and deposited in the receptacle 8%.

As required this receptacle may be cleaned out.

The fabric with its freshly spread coating, inspected and cleaned of foreign matter and lIl'11')l"fB(ti0nS, is now in the vaporizing chamber, and the apparatus now; to be described has for its function the drying of the coating and the recovery of the volatile solvents, which come from the coating in the form of vapors during the drying process; or the recovery of so much of these solvents as is commercially practicable. The drying operation, as" has been set forth, is per, formed by bringing the back .or uncoated side of the fabric into direct contact with, or close proximity to, heated surfaces, preferably rotary mangles heated by hot water, and preferably at the same time exposing considerable areas of the coated face in proximity to similarly heated backing plates. The result is that the fabric is dried mainly fr m the back outwardly through the coating, thus causing the solvent vapors topass off at the coated surface as the coating dries. The heating appliances are also preferably arranged so as to apply the heat to the fabric at successively and progressix'ely higher degrees of temperature, thus enabling the drying. operation to be more speedily effected, and preventing injurious results which would occur by passing the fabric immediately *into contact with or proximity to heating appliances at the highest degree of temperature.

It has already been explained that in the preferred construction illustrated the rear and lower portions ofthe vaporizing box are made up of a. series of hollow segmental backing plates secured together. This const r uction combines therewith two rotary heated mangle drums 8G and ST. The construction of each of these drums is 'similar and is shown in detail in Fig. at. The drum 86 which is therein shown is formed with two heads 38 and S9, and ,a'circumferentially hollow cylinder 90 boltedlth 'reto. The head 88 extends out through bearings in one of the circular sections 91 of the side plate 1. This drum 86, which is the rearward one, carries on the hub of the head 88 and keyed thereto a worm wheel 93. A worm 94 car ried by a shaft 95 driven from'any suitable motor secures the rotation of the drum. The hub of the head S8also carries a gear 96 which through an intermediate gear 97 iuterm eshing with a similar gear 98 on the shaft of the drum 87 secures the rotation .ofthe latter from the rear drum S6. The

opposite head 89 of the drum 86 extends out through a bearing in theopposi-te circular section Ol'of the opposite side plate 1. The hub of the head 89 is axially apertured as shown at 99, and the inner end of this aperture is covered by a cap 801. -A pipe 802 connects this cap and through it the aperture 99 with the circumferential chamber of the cylinder 90.

The drum 87 is similarly constructed operatech being driveinjas has been shown, from the drum 86 through the medium of the gearing described. For the purpose of reversi'n'grthe fabric. so as to keep the uncoated side against both drums, a .small drum 10,1 is located intermediate the drums 86 and 87, andjou'rnaled in theside platesof the'chamber, and maybe driven by the gears..130'and '131 fromthe intermediate gear 97. It will be observed that the coat- I injured.

The fabric runs from the drum 87 over an idler roll 103 to the exit opening from,

.1' the vaporizing chamber. This exit opening, shb'w'i i" in detail in Fig. 7,isformed between two rolls 104 and 105 journaled in the front plate 2. The fabric being thoroughly, dried at this point, these rolls may contact with,

the opposite faces thereof. Sealing blocks 106 of felt or suitable material seal the plate 2.

space between the rolls at the edge of the fabric, and sealing strips 107 and 108 of feltor other suitable material seal the lines where .the. rolls come adjacent the face The fabric passes from the exit opening to a suitable take-up device, a simple form of which is sufficiently shown in' Figs. 1. and 2. The take-up roll is indicated at 900, journaled in the'stand 901. A friction disk 902 is loosely mounted on the axis of the roll. A collar 903 is made fast to the aXis at the outside of the disk 902, and a second collar 904 is pressed against the opposite surface ofthe disk by a spring 905 abuttingagainst a collar 906 adjustably mounted on the axis of the roll. Thus upon the rotation of the disk 902 the take-up roll 900 will be rotated, but the construction described allows for a slip-between the disk and the roll when necessary. The disk 902 is driven by frictional engagement from adisk 907 keyed to a shaft 908, which shaft is driven by means of beveled'gears 909 and 910 from a shaft 911, the shaft 911 being in turn driven by a belt 912.-'running over. a pulley on the shaft of the drum 87. The friction drive disk 907 is shifted along its shaft 908 to vary the speed of the take-up roll according to the amount of fabric wound thereon by means of "a lever 913, the free arm of which "has an antifriction' roll 914 resting against the periphery of the woundq p cloth, while the other end is forked and fits a slotted collar forming a part offthe friction disk 907. This lever'913 is fulcrumed at 914 and a spring 915 holds it up against. the cloth. By the .use of a take-up such as just described,- and by driving the friction disk 9.02 at a slightly greater speed than that required to roll up the cloth, the cloth is pulled as it'diverges from the machine. The let-oft device also pulls upon the cloth, the amount of pull being governed by the weights hung'upon'the friction brake 401.

As a result,the cloth is kept snugly stretched in its travel through the vaporizing box. The mangle rolls are run at the same rate of jthrough the machine.

- with but peripheral speed, so that the cloth at all points is moving at the same linear speed and kept smooth and even in the direction of its width.

A hollow beating plate 700 is mounted between the side,frames 1, with its top sur face substantially in' line with the tops of the drums 86 and 87.

- The heating; and drying of the coating is preferably performed by the agency of hot Water, although any other desired heating agent may be circulated through the heating elements. Steam may also be used with satisfactory results, and connections are indicated in dotted lines to show how the steam may be circulated through the apparatus. about as high as is desired to dry some artificial leather fabric and release the solvent vapors. peratureof the steam has to be reduced to effect the desired results. YVater kept more readily at the required temperature, but either steam, water or other heating agent may be readily connected and circulated in theapparatus by any'suitable circulating system, which forms no part of the present invention.

If the freshly coated fabric be suddenly brought to a high degree of temperature the moisture and solvents suddenly turn into vapor and burst through the coating, forming pin holes and imperfections therein. In the present construction, therefore, the apparatus is arranged so that the successive sections thereofreached by the fabric in its travel are at successively higher degrees of temperature. 0 may be varied as desired to securethis result, but for convenient illustration of the principle the apparatus herein shown is provided two such sections. The hollow heating v pla te'700 and the 'hollow'backing ,plates 4 to 11 inclusive are maintained at one temperature, while the hollow backing plates 12 to 16 are maintained at a different and higher degree of temperature. The two drums are also capable of being maintained at independent and desired temperatures according as the results of practice may require. Y

The piping shown in 'full lines in the drawings, particularly'Fig. 3, is designed for the use of water as the circulating heating agent. In this case the pipes 450 and 451 are supply pipes. The pipe 151 branches, being connected by the branch452 to the hollow heating plate 700 and by the branch 453 to the hollow backing section 4:. The

A" temperature of 180 degrees is.

The sections of the apparatus If steam be used the temmay be atent-a hollow backing sections 4 to 11 inclusive are connected by the pipes 118. The exhaust pipes 454 and 455 connect respectively with the hollow heating plate 700 and the hollow back plate section 11, and these pipes converge into the exhaust pipe 456.

The pipe 450 is connected to the hollow back plate section 16; the hollow back plate sections 12' to 16 inclusive are connected by connecting the pipes and the exhaust pipe 4:57 extends out from the opposite hol low back plate section Suitable circulatory systems are provided connecting the pipes 451 and 456 on the one hand and, 450 and 477 on the other hand, to maintain the temperature in the latter at a higher degree than that in the former. By means of the connections described in considering the drum S6 and the similar connections employ'ed in connection with the drum 87, water is circulated through the hollow circumfercntial' chambers of the drum at required and desired temperatures, either the same as or different from the temperatures of the correspomling backing plates.

If. steam be employed the connections shown in dotted lines may be used instead of those shown in full lines, and the same general result he produced. In the case of the drums, however, the same connections may be used for either steam or Water. In the case of the use of steam there need be but one circulatory system, and the regulation of the temperatures for different sections may be effected by the use of reducing valves indicated diagrammatically at 122 throughout the system.

A prominent feature of this invention, as has been pointed out, is the carrying on of the process of reclamation of the solvent vapors with the use of air to an immaterial extent as an absorber of the vapor or as a drying agent. By immaterial it is meant that the amount of vapor absorbed by the air is a very small fraction of that recovered. To secure this result the vaporizing box is connected with a sditable condenser, and the circulation from the vaporizing box through the condenser and back to the va porizing box is aided if necessary by means of a fan. The drying of the fabric being effected by the direct action of the heating surfaces, and the space inclosed in the vaporizing box being kept small, the solvent vapors are given off rapidly and in large volume. Passing into the condenser these vapors are condensed and the vacuum which tends to form in the condenser is practically neutralized in the rush of the incoming vapors. There is little need, therefore, of air in the apparatus to maintain'the interior at substantially atmospheric pressure, but enough-leakage of air into the vaporizing chamber takes place to prevent the forma tron. of any substantial vacuum therein, and

this is all the air which is requisite in the carrying on of the process. The result is that-the machine carries out the: process in a highly efficient manner, and the air so far as it is used serves merely to carry the vapors around and maintain the pressure within the chamber at about atmospheric pressure, and without material absorption of the vapors.

'lhe'outlet from the condenser is carried to a point immediately over the fabric where it first enters the apparatus, so that the circulation of vapors and such air as there may be is at its lowest temperature when it strikes the fabric, and the outlets from the vaporizing box to the condenser are arranged to take the vapors directly into the c'ondenser.

The constructions for securing these rc-- sults may be various. but in the form illustrated an ordinary form of condensing tank of sutiicientdimensions is shown at GQO mounted upon or directly over the vaporizing box. sloping slightly toward the rear end, and provided with coils of piping 601 throughwhich a suitable refrigerating agent is circulated. Outlets are provided in the \nporizing box at ($02. (303 and (iOig that is. respectively at the end of the drum 86. after the fabric has traveled about half its distance around the drum in the space between the two drums. and at the end of the drum 87 as the fabric is about to leave the drum. These outlets are connected by the pipes (307 to a. fan or blower (506 of'any suitable material, and located on top of the vaporizing box and at the lower end of the condenser. The fan 606 is driven in any suitable manner, as by a belt 07 running over a pulley on the shaft of the drum 86. The outlet from the condenser is by a pipe 608 which passes through the hood 301 and enters the chamber 23 from the top. The circulation from the condenser coming through the pipe ($08 then passes through the slots 21 and .22 into the vaporizing box and follows the top surface of the fabric, being directed by suit able baliie plates ($09 and (510, as well as by the table 7 9 and the top of the vaporizing box to the outlets which are located at the ends of the drums. By reason of this con struction the air which enters the vaporizing device substantially freed from volatile solvents passes in a general longitudinal direction along the coated face of the fabric but gradually is diverted toward the opposite sides to the outlets, so that the action of the circulating current is both longitudinal of the Web of fabric and laterally thereof,

Lee

condition so that the volatile contents of the coating may be driven out through thisplastic surface as the coated fabric passes over the heating device without producing pits and pinholes such as are produced when an escaping bubble of volatile material punctures the seared surface of the coating is usual in fabric coating apparatus. By reason of the fact that the coated fabric is carried around a drum the outer face of the coating is slightly stretched as the fabric is bent about the drum. tends to separate. slightly the molecules of thecoating at or near the surface of the coating and the tension upon the surface caused by this bending action aids in expelling the small bubbles of volatile material which are produced by the application of the heat through the drum. \Vhen the blade 73 is employed as an auxiliary scraping knife this passageway for the circulation is blocked. An opening from the chan'iber 23 is accordingly provided in the back of the frame at (320 which opening is otherwise closed by a gate (v-21. operated from the outside of the apparatus. From this opening (320 the circulation passes between the frame 20 and the front plate '2 through the slot?) and on through the vaporizing chamber as before.

'lhe-comlensed solvent vapors may be drawn off from the condenser in any suit able manner, and for'that purpose an ordi nary trap on the principle of an ordinary steam trap is provided, indicated diagrammatically at 650.

The entire. apparatus is made of metal, as has been before pointed out. and danger from sparking is practically eliminated be-- cause of the metal construction and the. ground connections througl'r the steam or water pipes. In addition, asteam spray is admitted at (340 near the middle of the. chamber, and this serves to preventfurther sparking and a still further safeguard is provided in the vent pipe or flue 126 of large size opening directly into the top of the chamber. and provided with a suitable check valve 129, so that in case of any ex plosion this check valve will open and provide a vent so that no injury will be done to the apparatus or the building in which it is located.

Windows or lights may be provided at suitable places in the Walls of the chamber for inspecting the interior. such as shown for example at 76.

It will thus be seen that the apparatus is one which While having high efficiency in the drying of the goods; the condensing of the vaporsand the handling of the fabric in large quantities, requires but little attention because of its automatic action. The fabric enters and leaves the apparatus at the same end so that it'may be watched and This action controlled by a single operator. The entire length of the fabric may be dried and the solvents recovered. A wrapper, that is a piece of plain uncoated fabric, is attached to the end of the coated fabric as it passes into the chamber. and may be left in the apparatus so that succeeding lengths of the fabric may be readily drawn through the machine. If, any reason occurs for running the fabric lau-kward. the spreading knife may be raised and the direction of feed reversed by simply reversing the driving mechanism of the apparatus.

The apparatus occupies but a con'ipara-. tively small space. Air not being used as a drying agent the space required for the collection 'and circulation of the solvent vapors is reduced to a minimum. Furthermore: since little of the vapors is absorbed by the air present. the maximum of solvenn vapors is condensed and recovered. Owing to the fact that the air present has an immaterial function as a drying agent or asan absorbent of the vapocs. the maximum amount of etliciency is obtained in this apparatus. The heat required to vaporize the solvents is not expended and wasted in heat ing the air. nor is the energy required for refrigeration wasted by re-cooling the air.

The invention having been fully described; what is claimed as new and desired to be secured by Letters Patent. is:

1. An apparatus of the, class described comprising a rotary heated drum. meansfor guiding the coated fabric around said drum with its back against the same and means for maintaining a volume of gas containing a solvent in contact with the face of saidcoating whereby the drying of the face of the coating will be retarded and the expulsion of volatile material from the coating.

will [proceed from the fabric toward the face of the coating.

2. An apparatus of the class describedcomprising a rotary heated drum, means for guiding the coated fabric around said.

drum with its back against the same and means for maintaining a volume of gas containing a solvent in contact with the face i of said coating througl'iout the entire'heated area whereby the drying of the face of the coating will be retarded and the expulsion of volatile material. from thecoating will proceed from the fabric toward the face of the coating. i

3. In' an apparatus of the class described comprising a v porizing chamber, a rotary heated drum located in said vaporizing chamber. means for guiding the coated fabric around said drum with its back against said heated drum and means for maintair'b 'ing in contact with the face of said coating a circulating current of -.gas containing it solvent whereby the drying the face at the coating will be retarded and the expul sion of volatile materials from the coating Will proceed from the fabric toward the face of the coating.

4. In an apparatus o f-the character described comprising a vaporizing chamber and heating means in said chamber consisting of'a series of heating elements of progressively increasing temperature, means for guiding the coated fabric over said heating means with its back toward the same and in,

a direction whereby the fabric will be subject to tire influence of gradually increasing temperature and means for maintaining in contact with the face of said coatin a voltarvelements of said manglcs, means for maintaining in contact with the face of said coating a circulating current of gas containing a solvent whereby the drying of the face' of the fabric will be retarded and the expulsion of volatile I materials from the coating will proceed from the fabric toward the face of the coating.

(5. An apparatus of the character described comprising a vaporizing chamber, a condensing chamber,condensing means connected with said condensing chamber, heating means located in said vaporizing chamber. 'means for guiding, the fabric through said vaporizing chamber with. its back toward said heating mcansfand means for inducing a circulation directly from the face of the fabric through the condensing chamher and back to the face of the fabric ad jacent to the inlet through which the fabric is introduced into the vaporizing chamber.

7. An apparatus. of the character described comprising a vaporizing chamber,

- a condensingchamber, condensing means connected with said condensing chamber, heatingmeans located within said vaporizing chamber, means for maintaining succes, 've sections of said heating means at successively higher temperatures, means for guiding the fabricthrough said vaporizing chamber in proximity to said heating means, aniline-ans for inducing a. circldatioi'i directly from the face of the fabric through the condensing chamber and directly back to the face of the fabric adjacent to the inlet through Which the fabric is introduced into the vaporizing chamber.

8. An apparatus of the character described comprising a vaporizing chamber, a condensing chamber, condensing means connected with said condensing chamber, a rotary heated mangle located in said vaporizing chamber, means for guiding the fabric through said mangle with its back against the rotary element thereof, and means for inducing a circulation directly from the face of the fabric through the condensing chamher and directly back to the face of the fabri .1 and in the same direction as that of the movement of the fabric.

9. An apparatus of the character dcscribcd comprising a vaporizing chamber, a condensing chamber, condensing means connected with said condensing chamber, a plu 'rality of rotary heated iii-angles located within said vaporizing chamber, means for maintaining successive sections of said mangles at successivelyhigher temperatures,

-means for guiding the fabric through said chamber with its back against the rotary elements of said mangles, and means for inducing a circulation directly from the face of the fabric through the condensing chamber and back to the face of the fabric and in. the same direction as that of the moven'ient of the fabric.

10. An apparatus of the character described con'iprising a vaporizing chamber, a condensing chamber, condensing means connected with said condensing chamber, a mechanical circulation inducer having a direct connection with the fabric inlet of said vaporizing chamber, condensing chamber and inducer whereby a constant circulation. is maintained therethrough, heating means located in said vaporizing chamber, means for guiding the fabric throughv said vaporizing chamber with its back toward said heating means. i

.11. An apparatus of the character described comprising a vaporizing chamber, a condensing chamber, condensing means connected with said condensing chamber, a mechanical circulation inducer and direct connections between said vaporizing chamber condensing chamber and inducer vaporizing whereby a constant circulation is maintained therethrough, heating means located in said vaporizing chamber, means for guiding the fabric through said vaporizing chamber with its back against said heating means, and means for maintaining the fab ric under tension during its passage through v the vaporizing chamber.

12. An apparatus of the character described comprising a vaporizing chamber, a condensing chamber, condensing means connected with said condensing chamber, a mechanical circulation inducer and direct connections between said vaporizing chamber, condensing chamber and inducer i scribed comprising a vaporizing chamber, a.

whereby a tained tha'ethrough. heating means located in said jvaporizi ig('liaiiibei'.' means for guiding the fabric through said vaporizing chamber with its back againstsaid heating means. and mains for maintaining the fabric centered during its passage through the vaporizing chamber.

13. An apparatus of the character decoifileiisiiig chamber, condensing means connected with said condensing chamber. means located \vithin'the aporizing chamber for drying the coating and vaporizing the soll a vents thereof without the aid of air as a maof the vaporizing chan'iber of movement of said fabric as it approaches terial drying and means for guiding of said vaporizing chamber and means for causing a circulation of the gaseous contents in the direction vaporizing agent, and

; the heating means. 1 p

l i. An apparatus 'of' the character described comprising a'vaporizing chamber, a

' condensing chamber; condensing means coli- 1iecte.(l with said condensing chamber, means located within the 'aporizing chamber for drying the coating and vaporizing the solvents thereof vithout the aid of air as a. H) material drying and vaporizing agent, and

means for guiding the. fabric into and out of thev iporiziug cliainbeat the same end thereof andm ians for causing a circulation ol the gaseous contents of, the vaporizing aacliaiiiber in the direction of movement of said fabric as it approaches the heating nea'ns. V

15. An apparatus of the cha'actcr described comprising avaporizing chamber, a

40 condensing chamber, condensing means connected with said condensing chamber. means located within the vaporizing chamber for v drying the coating and vaporizing the solvents thereof, without the aid of air as a material drying aiid vaporizing agent. means for guidingthe fabric into and out of the vaporizing chamber at the same end thereof', and alet-off and take-updevice for said fabric located;ad acent said end of said chamberwhereby the tension of the fabric in passing through the chamber is con trolled. v

16,. An apparatus of the -cha'acter described comprising a vaporizing chamber, a condensing chamber, condensingmeans con-'- nected with said condensing chamber, a-nautomatic trap for automatically removing the condensate from said condensing chamber, a rotary heated drum located within said va- 0 porizing chambcr,means for guiding the fabric through said vaporizing chamber with its back against the periphery of said drum, means f r closely inclosing the periphery of tie drum covered bv said fabric, and means constant circulation is main-' the fabric into and outfor inducing a circulation directly from the face of the fabric at the periphery of said drum through the condensing chamber: and

directly back to the face of the fabric. o

w 17. An apparatus ofthe' character described comprising a" vaporizing chamber, a

condensingchamber,- condensing means connected with said condensing chamber, an automatic trap forautomatically removing the condensatefrpm said condensing chamber,

a rotary heated "drum llilVlng a' crowned periphery located Within said vaporizing chamber, means for guiding the fabric through said vaporizing chamber with its back against 'thelperiphery of said drum, means for 'closely inclosing the periphery of the drum covered by said fabric, and means for inducing a circulation directly from the face of'the'fabric at the periphery'of said drum through the condensing chamber and directly back-h) the face of the fabric.

18. An apparatus of the character de-.

scribed comprising a' vaporizing chamber, a

condensing chaniber, condensing means connected with said condensing; ClifllIlbBlQllGilt- .ing means loca'tedin said 'aporizing chamber and comprising a rotary drum having a hollow circumferential chamber and hollow backing plates in close proximity to saiddruin, means for circulating water at high I tempeiiitnrc "through said circumferential chamber and through said backing plates, means for guiding thefabric around into and out of the vaporizing chamber and around the periphery of said drum with its back thereagains't, and means for passing the solvents vaporized from the fabric at substantially atmospheric pressure from the vaporizing tofthe'. condensing chamber ivith immaterial absorption by the air,

ments, and means for passing the vaporized solventsatsubstantially atmospheric pressure fr'oin the vaporizing to the cendensing chamber \vith innnaterial' absorption by the a-ir;*' 20.- An apparatus" of the character described comprising a vaporizing chamber, a condensing chamber, condensing means connected with said condensing chamber, ing means located in said VELPQI'lZdIlg chamber, means for guiding the fab-r10 through heatsaid vaporizing chamber in proximity to said heating means, means for passing the V as , vaporized solvents at substantially atmosber, means for g'uidin the fabric through said vaporizing cham er in proximity to said heating means,-means for passing the j vaporized solvents at substantially atmospher'ic pressure from the vaporizing to the condensingv chamber 4 with immaterial absorption by the air, piping connected to the heating means and servlng as electrical connections to ground the apparatus and pre:

vent sparking, and means for maintaining the fabric under tension 'durlng its passage through. the vaporizing chamber.

f 22.,An apparatus of the character describedcomprising a vaporizing chamber, a condenslng chamber, condensmgmeans coni nectedvwith said condensing chamber, heating means located in said vaporizing chamber, direc't connections between said vaporizingchamber and condensing chamber, and means. for passing the vaporized solvents at substantially atmospheric pressure through i said connections with immaterial absorption by the-air" I '23.- An apparatus of the class described.

\ compr sihg a vaporizing chamber, and heating means in said chambe ents'of different I iding the coated fabric adjacent to saidheating means, means vfor maintaining incontact with the face of" the drying will proceed fromflthe fabric r consisting of a plurality of heatingf l' temperatures, means for said coating a volume of gas containing a [solventvapor whe'reby the drying of the face of the vcoating will be retarded so that toward theface of the goods.-

24. An apparatus of 'thecharacter de- 4 scribed, comprising a vaporizing chamber,

a condensing chamber,- A condensing means connected with said condensing chamber,

heating means in the vap'orizing chamber,

means for guiding fabric'ithrough said chamber, 'means for inducing a circulation directly from. the face of said fabric through the condensing chamber, and means tor passing vaporized solvents at substantially atmospheric pressure from the vaporizing to'--the condensing chamber without material absorption-by the air.

25. An" apparatus of the class describedcomprising a vaporizing chamber, a condensing chamber, condensing means coning means in said vaporizing chamber,

means forguiding the fabric through said chamber, means for inducing'a circulation longitudinally and laterall of the direction of movement of I the fa ric and thence through the condensing chamber and back to the face of the fabric adjacen tsto the inlet through which the fabric is introduced into the vaporizing chamber. x

26. An apparatus of the character described comprising a vaporizing chamber, condensing mean's connecte'd with said vaporizing chamber, a rotary heated drum located in said vaporizing chamber, means for l guiding the fabric through said vaporizing chamber with its back against said rotary heatingadrum, outlets leading from adjacent the ends of said drum to said condensing chamber and means for inducing the circulation directly from the face of the fabric through said outlets to the" condensing chamber and back to the face of'the fabric adjacent the inlet-through which thefabric is introduced i'nto thef vaporizing chamber. 27. An apparatus of the-character described comprising a'vaporizing-chamber, a condensing chamber, condensing means connected with said condensing chamber, means located withinthe vaporizing chamber for drying the coating and vaporizing the solvent thereof'without the aid of air as a material drying and vaporizing agent, means for guiding the fabric'into and out of said vaporizing chamber, means for inducing a circulation of the' solvent vapor toward the condenser'by the use of air to carry the vapors and to maintain atmospheric pressure Within the vaporizing chamber.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses."

CHARLES F. HOPEWELL.

Witmsses:

JOHN 0. EDWARDS, NATH N'HEARD.

nected with said condensing chamber, heat- 

